Vishal Tiwari spacemonkeyvt

Introduction to HTTP

Starting from the top...

Classical Inheritance in Ruby

For programmers who are new to Object Oriented Programming, the ideas behind classical inheritance can take some getting used to. This article walks you through the syntax of defining class inheritance in Ruby with explanations of each OOP feature along the way. You will have created many inheriting classes and used them in Ruby code by the end of this exercise.

Create a new Ruby code file and copy the code examples into it as you go. Run the file with the provided driver code and read the output. Try writing your own driver code to try things out new concepts as they're introduced.

Unix Commands - Discovery

Part I

Enter these commands individually on the UNIX prompt (in your vagrant ssh session). Try to interpret the output. Research their purpose on google as needed, and don't be afraid to experiment.

pwd
cd ~/
ls -al
echo hello world
date

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

Stores data elements based on an sequential, most commonly 0 based, index.
Based on tuples from set theory.

MySQL

Getting started:

	# Sample implementation of quicksort and mergesort in ruby
	# Both algorithm sort in O(n * lg(n)) time
	# Quicksort works inplace, where mergesort works in a new array

	def quicksort(array, from=0, to=nil)
	if to == nil
	# Sort the whole array, by default
	to = array.count - 1
	end

	> nest = [1,2,3, {name: "Vish", address: ["123 fake add", "456 fake add", city: ["toronto", "north york"]]}, ["thingy", "thingy2"]]
	#=> [1, 2, 3, {:name=>"Vish", :address=>["123 fake add", "456 fake add", {:city=>["toronto", "north york"]}]}, ["thingy", "thingy2"]]

	> nest[3]
	#=> {:name=>"Vish", :address=>["123 fake add", "456 fake add", {:city=>["toronto", "north york"]}]}

	> nest[3][:address]
	#=> ["123 fake add", "456 fake add", {:city=>["toronto", "north york"]}]

	> nest[3][:address][2]

	CREATE///////////////////////////

	CREATE TABLE student (id INTEGER PRIMARY KEY, first_name TEXT, last_name TEXT, age INT);

	.tables /* Shows the table created */

	.schema /* Shows the schema used to create the table */

	SELECT * FROM student; /* Show all rows in the student table */

	ActiveRecord cheat sheet / EXAMPLES

	INSTALL
	=======
	$ gem install activerecord
	in GEMFILE: gem ‘activerecord’

	REQUIRE
	=======
	require ‘active_record’